This invention relates to an air bag assembly, and more particularly to an air bag assembly including an inflatable air bag cushion and one or more selectively actuated vents within the air bag cushion. The vents are selectively actuated in conjunction with control of the inflated profile of the air bag cushion such that venting is matched in a predefined manner to the inflated profile characteristics of the air bag cushion.
It is well known to provide an air bag assembly including an inflatable air bag cushion for protecting the occupant of a transportation vehicle. In an automotive vehicle, such air bag assemblies are typically located within the hub of the steering wheel and in a recess in the vehicle instrument panel for protection of the vehicle occupants seated in opposing relation to such assemblies. Additional air bag assemblies may be located within the seats and/or door panels for protection of the occupants during a side impact event.
Air bag assemblies typically include an inflatable cushion, and a gas emitting inflator mounted in fluid communication with the inflatable cushion. In a driver side air bag module, a base plate typically supports the inflator at the interior of the vehicle steering wheel or other appropriate location opposing the occupant to be protected. The mouth of the air bag is disposed in surrounding relation to the inflator with a perimeter portion of the mouth being held between the base plate and an overlying retainer to effect a secure relation between the inflator and the cushion. In a passenger side assembly, the inflator is typically held within a trough-like housing with the air bag cushion being held along the walls of the housing such that inflation gas passes from the inflator into the cushion upon activation of the inflator. Both driver side air bag modules and passenger side air bag modules are well known.
In the past it has been advocated to adjust the inflated profile of air bag cushions by the selective extension of tethering elements. By way of example only, representative systems for use in effecting a controlled deployment depth by selective release of tethering elements are disclosed in U.S. Pat. Nos. 5,887,894 to Castagner et al., and 6,390,501 to Greib et al. the teachings of which are incorporated by reference as is fully set forth herein.
The present invention provides advantages and alternatives over the prior art by providing an air bag assembly including one or more selectively activateable vents which may be opened on command during deployment of the air bag cushion such that venting is selectively controlled in a predefined manner. The control of such venting characteristics thus provides an additional degree of control over the deployment characteristics of the air bag cushion.
According to one aspect of the present invention, an air bag assembly is provided having an inflatable cushion selectively deployable to a controlled geometry with a controlled venting character. The venting characteristics are adjusted in view of crash severity and/or the position of the occupant and/or the size of the occupant and/or seat belt usage by the occupant to be protected such that an air bag cushion of desired volume and venting capacity is available to protect a range of occupants under different conditions during impact events of various levels of severity. The air bag assembly of the present invention provides a simple, cost effective and highly reproducible mechanism for controlling the venting character of the air bag cushion.